Effect of arteriovenous difference in measuring renal function by single-injection plasma clearance: role of bolus.

Error estimates for arteriovenous difference were calculated by two models, a lag time model and a compartmental model, using Tc99m-diethylenetriaminepentaacetic acid (DTPA) plasma clearance curves from 40 subjects and Tc99m-MAG3 (mercaptoacetyltriglycine) curves from 18 subjects. It was found that correcting for the effect of the initial bolus largely cancelled the conventional arteriovenous difference, so that the net error was negligible.